Miner&#39;s safety-lamp.



' M. ALBRECHT. MlNEHs SAFETY LAMP. APPLICATION 'lLED NOV. 24.19.13. 1,153,003. PatentedSept'. 7, 1915.V

prENT OFFICE.

MARTIN ALBRECHT, or FRANKFoRT-oN-THE-MAIN, GERMANY.

MINERs SAFETY-LAMP.

Specification of Letters Patent.

Patented Sept. '7, 1915.

Applieatiou filed November 24, 1913. serial No. 802,819.

To allrchom 'it may concern:

Be it .known that I, MARTIN ALBRECHT, a

citizen of the German Empire, residing attofore known principle of a diffusion chamber covered with a porous plate and connected with one limb o f a U-passage filled with liquid so that, owing to the rise or fall in.

pressure produced in the diusion chamber by gaseous changes, the level of the liquid in the passage is displacedas is known from ,the physical principle of the barometer.

The heretofore known instruments could not be readily carried about and used where.

most necessary to detect gaseous alterations in mines and were usually xedly secured in a' vertical position so that they could not be shaken. In the present invention the instrument is so constructed that it can be carried about to detect gaseous changes without affecting its reliability in operation. l

The drawing illustrates one practical construction of the invention in cross section.

The base l contains a suitable battery 2 which is inclosed in a vessel 3 having a cover 4 of insulating material. On the plate,I 4 are contact springs which connect the battery with an incandescent' lamp 6. The lamp 6 has its neck loosely fitted in a socket 8?; to hold the lamp in placeits top presses against .a plate l1 of leather or felt attached to a reflector 10 suitably fixed within the upper end of an inclosing glass cylinder 9. A spring 8 in the socket 8a is compressed by the 'insertion of the lamp neck therein and ifthe lamp globe should be broken saidv spring will throw out the'broken lamp so that the circuit is immediately broken..

This is very important in case, in the presence of fire-damp, th'e glass-cylinder 9 and also the lamp globe should be broken.

A diffusion chamber 12 is formed above -underlay 23. be brought intodirect communication with `red side.

the reiector 10 and is covered by a' diffusion plate '13 of suitable material sea-led at its edges by a screw ring 22-and an elastic This diffusion chamber can the outside air or with the interior of the lamp, by means of a valve 14 which can be actuated by means of a rod 24, lever 25 and push button 15.

Connected with the diffusion chamber between the lamp andthe side of the glass cylinder 9 is a U-shaped passage 16 preferably formed in glass and of very small bore which contains a colored :liquid 16a that under normal pressure stands at uniform height. The two walls of the limbs of thev passage are each preferably of .a special color, or distinctively markedfor instance by colored glass beads 17 and 18. The limb 17` will hereafter be called the green side,

esv

and the limb 18 will hereafter be called the The pressure in ^the diffusion chamber 12 lchanges according to the alteration in the gaseous state of the exterior atmosphere in known manner owing to the porous cover plate 13, and according to thel pressure in chamber` 12 the level of the liquid in the limbs of passage 16 varies. i

When such lamp is brought into an atmosphere containing 'fire-damp, then the plus pressure accumulates in the diffusion chamber. Consequently, when fire-damp is present, the level of the liquid Aon the green side will sink andthe red side will rise. This is easily recognizable' and will indicate the presence of as little as 3% of fire-damp.

When equality between the outer air and the air in the diffusion chamber is attained, the

liquid in the red and green limbs will again assume a uniform level. In this manner there is provided an absolutely reliable indicator for fire-damp. In the presence of so called injurious gases which are heavier than air (CO2) the Apressure'in chamber 12 will be minus and the liquid will rise Aon the green side. The kind of exterior gases can therefore be determined with certainty.

By opening the valve 1,4 the level of the brought to the same height. The glass cylinder 9 may be connected to a bottom plate 9a which has a flange 9b screwed onto an opposed' flange 1b. on theupper end of the casing 1. The lamp socket 8a isattached to the .plate 9?. By unscrewing 9ab the casing 1 `liquid in both limbs can be instantaneously jf" .15 one end with said chamber, and interposed The -passageV being beside the lamp vthe user can easilyseein which leg of the pas- 5 sage the liquid is highest and be thus warned as to the condition ofi-,the exterior atmosphere.

The advantage of the small -column of liquid -in the passageconsists in this that despite its smallness it gives a very effective signal automatically as soon as mine-damp occurs. The small amount of liquid in'the passage does not darken the lamp much. Only a slit of a few millimeters is covered up by the liquid within the range of the lamp. But as soon as mine-damps occur which could cause the least peril, the liquid begins to move on account of the .smallness of' the column, similar to boiling water. The red liquid boils up and produces an extraordinarily intensive, flickering light which 4cannot be overlooked at all by the miner. As soonas for instancefan excess ofipressure takes place in the diffusion chamber,'the column of liquid in the limb i's pressed downward and 'as the'A volume is small it does not .take long until the level of the' liquid reaches the top of the passage and the gas can then,y escape through the other limb into the outer air. Not only by the passage of the gas bubbles through the left limb but also by the return of the liquid into the right limb after the escape of one gas bubble, the red iuid is shaken up in an intensive manner and an eective, flickering light is produced. -This automatic indication of the change of gases is, of course, eX- traordinarily important for the miner connot always watch the device in order to discover every movement of the same at once.

What I claim is:

l. The combination of a lamp, a member having a diffusion chamber adjacent saidV lamp, anda U-shaped passage carrying a iuid therein, said passage communicating at y between the lamp and the spectator.

,fkg 2. Thecombination of a lamp, a member 4 having a dili'usion chamber above said lamp, V A,and a U shaped passage connected at one end with said chamber, the limbs of said passage l being adapted to display distinctive colors, substantially as described.

3. An apparatus for the purpose specified, comprising a lamp, a casing having a diffusion chamber, and a U-shaped passage carrying a fluid therein, said passage being of very small cross section connected with said diiiusion chamber and depending beside the lamp, and a liquid in said passage.

4. An apparatus for the purpose specified, comprising a base, a lamp attached thereto, a casing surrounding the llamp and having a diusion chamber above the lamp, and a U-shaped passage carrying a iiuid therein,

said passage being connected with said diffusio'n chamber and depending beside the I lamp, substantially as described.

5. The combination of a lamp and a member having a diffusion chamber, and a U- shaped passage connected with said ,chamber and depending beside the lamp, and a vent valve in said diffusion chamber.

6. The combination of a. base, a. cylinder detachably attached to the base, having a diiiusion chamber in its upper part, and a U- shaped liquid holding passage connected with said diffusion chamber, a lamp socket at the bottom of said upper portion, a lamp removably fitted in said socket, a reflector below `the diiusion chamber adapted to hold said lamp in the socket, and a spring in the socket for ejecting the lamp if broken.

-7. In an appara-tus for indicating changes changes inatmospheric pressure will be com-A medium' municated to said indicating through said diiiusion chamber, substantially as described.

In testimony whereof I affix my signature in the presence of two witnesses.

4 MARTIN ALBRECHT. Witnesses FRIEDRICH CARL WENTZEL, MAX HERMANN HrPNEn. 

